Continuous catalytic reduction of p-nitrophenol confined within two-dimensional nanochannels in laminar MoS2 membranes

MoS2 nanosheets exhibit high specific surface areas and pronounced catalytic activity and so are an alternative to noble metal catalysts. However, the deactivation of these materials because of aggregation and loss during catalytic reactions is a concern. The present work proposes a catalytic membrane reactor concept based on two-dimensional nanochannels formed in MoS2 laminates and demonstrates the continuous reduction of p-nitrophenol (p-NP). Laminar MoS2 membranes were fabricated by pressure-assisted filtration using MoS2 nanosheets prepared via Li intercalation. These membranes provided a flux of 26 L m−2h−1 with a p-NP conversion of approximately 90% at 0.5 bar. The flux and conversion could be controlled by varying the applied pressure. The present MoS2 membranes showed stable flux and conversion values during a 5 h permeation test and demonstrated the continuous conversion of p-NP into p-aminophenol without any loss or aggregation of the MoS2 nanosheets compared with a reaction in a batch reactor. Furthermore, surface functionalization of MoS2 nanosheets using iodoacetic acid was found to improve the stability of the laminar structure during drying. These laminar MoS2 membranes also exhibited higher catalytic performance than has been reported for metal-based membrane reactors. This study establishes an effective approach to constructing two-dimensional nanochannel reaction spaces using MoS2 nanosheets.